The present invention relates to color-change laminates and toy sets with the use of the same. More particularly, it relates to color-change laminates which can undergo a variety of changes not seen in the ordinary state upon absorption of a liquid, e.g., water and can recover the original state upon completion of drying and toy sets with the use of the same.
Converted papers and sheets are known which comprise a substrate and formed thereon a porous layer containing a low-refractive-index pigment and which, upon liquid absorption, becomes transparent and develops the color tone of the underlying layer (see JP-B-50-5097, U.S. Pat. No. 4,810,562; the term xe2x80x9cJP-Bxe2x80x9d as used herein means an xe2x80x9cexamined Japanese patent publicationxe2x80x9d).
In these converted papers and sheets, the underlying layer is shielded by the porous layer in a dry (absorption of no liquid) and, upon liquid absorption, the porous layer becomes transparent and thus the color tone of the underlying layer is perceived. When the hiding properties of the porous layer are improved, the transparency upon liquid absorption is deteriorated. When the low-refractive-index pigment is added only in a reduced amount to enhance the transparency upon liquid absorption, on the contrary, there arises another problem that the hiding properties in a dry state are deteriorated. When the underlying layer has a color tone with a relatively high lightness (for example, a fluorescent color tone), the low-refractive-index pigment should be added in an increased amount to shield the color tone. As a result, the transparency upon liquid absorption is lowered and thus the vivid color can be hardly perceived.
On the other hand, JP-A-1-260075 proposes moisture-sensitive color-changing printing agents containing finely particulate silicic acid and brilliant pearl pigments to be printed on various substrates (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d). In a dry state, these moisture-sensitive color-changing printing agents show a white color attributable to the finely particulate silicic acid. Upon moistening, the finely particulate silicic acid becomes transparent and the color tones of the brilliant pearl pigments are perceived. However, these color tones attributable to the brilliant pearl pigments are less vivid compared with the color tones of common dyes or pigments. In addition, these printing agents have a disadvantage that the color tones of the substrates are restricted to black or dark colors so as to sufficiently perceive the color tones of the brilliant pearl pigments.
An object of the present invention is to overcome the problems encountering in the conventional laminates having porous layers. Namely, the present invention aims at providing color-change laminates which can establish both of the hiding properties in a dry state and the transparency upon liquid absorption and can be used in applications in various fields including toys, ornaments and designs, and toy sets with the use of the same.